The relationship between air pollutants and gestational diabetes: an updated systematic review and meta-analysis.

PURPOSE: Air pollution is an environmental stimulus that may predispose pregnant women to gestational diabetes mellitus (GDM). This systematic review and meta-analysis were conducted to investigate the relationship between air pollutants and GDM. METHODS: PubMed, Web of Science, and Scopus were systematically searched for retrieving English articles published from January 2020 to September 2021, investigating the relationship of exposure to ambient air pollution or levels of air pollutants with GDM and related parameters, including fasting plasma glucose (FPG), insulin resistance, and impaired glucose tolerance. Heterogeneity and publication bias were evaluated using I-squared (I2), and Begg's statistics, respectively. We also performed the subgroup analysis for particulate matters (PM2.5, PM10), Ozone (O3), and sulfur dioxide (SO2) in the different exposure periods. RESULTS: A total of 13 studies examining 2,826,544 patients were included in this meta-analysis. Compared to non-exposed women, exposure to PM2.5 increases the odds (likelihood of occurrence outcome) of GDM by 1.09 times (95% CI 1.06, 1.12), whereas exposure to PM10 has more effect by OR of 1.17 (95% CI 1.04, 1.32). Exposure to O3 and SO2 increases the odds of GDM by 1.10 times (95% CI 1.03, 1.18) and 1.10 times (95% CI 1.01, 1.19), respectively. CONCLUSIONS: The results of the study show a relationship between air pollutants PM2.5, PM10, O3, and SO2 and the risk of GDM. Although evidence from various studies can provide insights into the linkage between maternal exposure to air pollution and GDM, more well-designed longitudinal studies are recommended for precise interpretation of the association between GDM and air pollution by adjusting all potential confounders.

Effect of nanocurcumin and fish oil as natural anti-inflammatory compounds vs. glucocorticoids in a lipopolysaccharide inflammation model on Holstein calves' health status.

Curcumin (CUR) and fish oil (FO) are among the most well-known types of natural anti-inflammatory compounds. The aim of this study was to assess the effect of nanocurcumin and fish oil vs. glucocorticoids on Holstein calves' health status. A lipopolysaccharide (LPS) challenge (0.5 µg kg-1 BW) was used to induce an acute phase response. A total of 42 male Holstein calves were randomized into 7 groups: negative control (CON), positive control (LPS, injected once), 250 mg/kg BW per day fish oil + LPS (FO250), 350 mg/kg BW per day fish oil + LPS (FO350), 2 mg/kg BW per day nanocurcumin + LPS (NCUR2), 4 mg/kg BW per day nanocurcumin + LPS (NCUR4), and 0.3 mg/kg BW dexamethasone (injected once) + LPS (DEX). The duration of this experiment was 11 days, with application of the LPS challenge on day 8. Calves were weighed on days 0, 7, 9, 10, and 11 to record the average daily weight gain; diets offered and refused were recorded daily throughout the experiment. Blood collection and clinical scoring were conducted at successive time points until 72 h post LPS challenge. The data obtained also comprised rectal temperature (RT), respiratory rate (RR), heart rate (HR), concentrations of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), serum amyloid A (SAA), and haptoglobin (Hp). This experiment could not uncover significant effects of LPS, FO, NCUR, and DEX on the area under the curve (AUC) of the RT, HR, and RR; in addition, there was no difference between FO and NCUR vs. LPS in sickness behavior, however, DEX group significantly recovered faster than others (P < 0.01). There was no significant difference between groups in dry matter intake (DMI) and average daily gain (ADG) during three days post LPS challenge. The concentrations of TNF-⍺, IL-6, and SAA were lower in the DEX group (P < 0.05). Finally, no effects of FO and NCUR on cytokines and acute phase proteins (APPs) could be observed in this study. In conclusion, supplementation of FO and NCUR was not able to impact the acute phase response (APR) in calves, as levels of inflammatory cytokines and APPs as well as sickness behavior remained unchanged. It seems that the anti-inflammatory effects of FO and CUR on APR, as has been observed for other animal species, do not manifest that clearly in calves.

Clinical display, diagnostics and genetic implication of novel Coronavirus (COVID-19) epidemic.

COVID-19 pandemic can cause irreparable damage to the involved society. This study aimed to provide a summary of the up-to-dated clinical display, diagnostics, molecular and genetic implications for COVID-19 infected patients. In this review, 73 research articles published before 25 March 2020 were analyzed to better understand the clinical characteristics of patients and to introduce the available serological, hematology and molecular diagnostic methods. Apart from articles extracted from PubMed and Google Scholar, WHO (https://www.who.int/), NHC (National Health Commission of the People's Republic of China (http://www.nhc.gov.cn/), NICE (National Institute for Health and Clinical Excellence, https://www.nice.org.uk/), CDC (Centers for Disease Control and Prevention, https://www.cdc.gov/), and National Administration of Traditional Chinese Medicine (http://www.satcm.gov.cn/) were also accessed to search for eligible studies. Papers published between January 1, 2020, and 25 March 2020 were searched in English and the terms "2019-nCoV, Covid-19, Clinical Characteristics OR manifestation, method of detection, COVID-19 Genome and molecular test" were used. As the pandemic continues to evolve, there have been reports about the possibility of asymptomatic transmission of this newly emerged pneumonia virus. We highlighted the role of HLA haplotype in virus infection as HLA typing will provide susceptibility information for personalized prevention, diagnosis, and treatment in future studies. All the data in this article will assist researchers and clinicians to develop their clinical views regarding infected patients and to emphasize the origin of SARS-CoV-2 for diagnostics.

Liquid molasses interacts with buffers to affect ruminal fermentation, milk fatty acid profile, and milk fat synthesis in dairy cows fed high-concentrate diets.

We aimed to evaluate the effects of feeding sugarcane liquid molasses (LM) with or without a commercial buffer mix (BFM) on ruminal fermentation parameters, milk fatty acid (FA) profile, and milk yield and composition in dairy cows fed high-concentrate diets (35:65 forage-to-concentrate ratio). Eight multiparous Holstein cows (4 ruminally cannulated) averaging 165 ± 12 d in milk at the beginning of the study were randomly assigned to a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each period lasted 21 d with 14 d for diet adaptation and 7 d for data and sample collection. Cows were fed the following diets: (1) no LM or BFM supplementation (CTRL), (2) LM without BFM supplementation (MOL), (3) BFM without LM supplementation (BUF), and (4) LM plus BFM supplementation (COMBO). These 4 isonitrogenous and isoenergetic diets were formulated by replacing (dry matter basis) 5% ground corn with LM, whereas BFM replaced wheat bran at 0.8% of the diet. Significant LM × BFM interactions were observed for the duration of ruminal pH below 5.8, molar proportion of propionate, acetate-to-propionate ratio, milk proportions of trans-10 18:1 and total trans FA, and concentration and yield of milk fat. Feeding MOL and BUF alone were effective on reducing the time that ruminal pH remained below 5.8 compared with the CTRL treatment, and the COMBO diet decreased it further. A similar pattern was observed for the ruminal molar proportion of propionate. The milk proportions of trans-10 18:1 and total trans FA dropped significantly with BFM or LM supplementation versus cows fed CTRL, and the COMBO diet decreased these variables further. Note, however, that these changes elicited by the COMBO diet were not in the same magnitude as those caused by MOL or BUF fed alone. The ruminal molar proportion of acetate increased with the BUF diet and that of butyrate increased in cows fed MOL, but mean ruminal pH was not affected by treatments. Diets with LM resulted in increased concentrations of short- and medium-chain FA in milk fat. The yield of 3.5% fat-corrected milk increased significantly in cows fed MOL or BUF due to the improved concentration of milk fat. A trend and a significant increase for energy-corrected milk were observed with feeding MOL or BUF, respectively. Overall, inclusion of LM and BFM appears to reduce milk trans-10 18:1 FA and total trans FA by modulating ruminal pH and volatile FA profile in cows fed high-concentrate diets.

Human and Animal Fascioliasis in Iran: Systematic Review and Meta-analysis.

OBJECTIVE: The aim of this study was to investigate the prevalence of fascioliasis in humans, cattle, sheep, and goats, done by a systematic review in Iran. METHODS: Fifty articles were extracted including Iranian papers such as Google scholar, Magiran, Iran Medex, SID, and Pubmed. Out of these, 21 articles were selected for meta-analysis. Essential information for meta-analysis was extracted from papers and archived in Excel software for calculating by statistical analysis. The variance of each study was obtained using the binomial distribution. Heterogeneity of the studies was surveyed using I2 index. Data were analyzed using a random effect model. RESULTS: Of 21 collected papers, 1,275,506 samples from cow (507,152), sheep (454,882), goat (207,925), and human (105,547) had been surveyed in Iran. Eight studies were conducted on humans and 13 on animals. The prevalence rate obtained in humans was 3% with a confidence interval (CI) of 95% (1%-7%). Prevalence rate obtained in cows, sheep, and goats was 13% with CI of 95% (10%-16%). The highest level of prevalence was reported from cities in the North in animals with a prevalence of 14%. The highest level of prevalence was reported from Gilan in humans with a prevalence of 0.1%. CONCLUSION: The prevalence of the Fascioliasis in Iran has reduced in recent years, But the importance of the disease has not reduced and there is a possibility of an epidemic. Furthermore, in many cities of Iran, there is no study on the disease.

Effect of dietary inclusion of date seed (Phoenix dactylifera L.) on intake, digestibility, milk production, and milk fatty acid profile of Holstein dairy cows.

The objective of this experiment was to investigate the influence of ground date seed (GDS) on intake, digestibility, and milk yield and milk fatty acid (FA) composition of lactating Holstein cows. The experimental design was a 4 × 4 replicated Latin square with eight lactating dairy cows with an average milk production of 35.5 ± 1.5 kg and 75 ± 5 days in milk (DIM). Dairy cows were fed one of the four treatments contained 0, 2, 4, and 6% of diet dry matter (DM) GDS in replacement of wheat bran. All diets contained the same amount of forages (alfalfa hay and corn silage). Dietary treatments had no effect on DM intake (DMI), total tract apparent digestibility, milk yield, and milk composition. Increasing GDS linearly decreased concentration of C13:0 and increased cis-9 C14:1 and trans-11 C18:1 (vaccenic acid) (P < 0.05). A linear tendency for more C16:1 content in milk fat was observed with increasing GDS (P = 0.06). Feeding GDS resulted in a linear decrease (P < 0.01) in saturated FA (SFA) but increased milk fat monounsaturated FA (MUFA) and trans FA (TFA) (P < 0.05). Therefore, low levels of GDS (up to 6%) in the diet of Holstein dairy cows can beneficially modify milk FA composition without any adverse effects on intake, digestibility, and milk yield.

Effect of particle size and partial replacement of alfalfa hay by soya bean hulls on nutrient intake, total tract digestibility and rumen degradability of diets by Holstein steers.

This study examined the effect of alfalfa hay (AH) particle size and the replacement of soya bean hull (SH) for AH within the diet of restricted fed Holstein steers on dry matter intake (DMI), total tract digestion, ruminal digestion, ruminal pH and ammonia nitrogen content, and faecal pH. Four rumen-cannulated Holstein steers averaging 353 ± 9.6 kg of BW were assigned to a 4 × 4 Latin square experiment with four periods and a 2 × 2 factorial arrangement of treatments. Factor A was AH particle size (fine vs. coarse) and factor B was diet SH content (0% vs. 10%; substituted for AH). Steers were fed at 1% of body weight of TMR containing 400 g/kg forage and 600 g/kg concentrate. Chopping of AH to fine particles decreased (p = 0.01) amount of dietary materials retained on the medium sieve (8 mm). The inclusion of SH significantly increased (p = 0.01) materials retained on the 1.18-mm sieve and tended to decrease (p = 0.07) materials on 19-mm sieves. The inclusion of SH increased (p = 0.01) ether extract (EE) intake and increased (p = 0.07) DMI. Inclusion of SH increased (p = 0.01) EE digestion and decreased (p < 0.01) faecal pH. Neither AH particle size nor SH inclusion in diets affected (p > 0.10) the in situ ruminal degradability coefficients of DM ('a', 'b', 'c' or 'a+b'). No interaction of AH×SH was seen on nutrient intake, digestibility and in situ ruminal degradability of Holstein steers.

Growth performance, feed digestibility, body composition, and feeding behavior of high- and low-residual feed intake fat-tailed lambs under moderate feed restriction.

Two experiments were conducted to evaluate the effect of moderate feed restriction on productivity of lambs classified on the basis of phenotypic expression of residual feed intake (RFI). In Exp. 1, 58 fat-tailed Kurdi ram lambs (32.1 ± 4.2 kg BW) were individually fed, ad libitum, a pelleted diet (35% alfalfa hay and 65% concentrate). Feed intake and ADG were determined for a 6-wk period and 3 feed efficiency measures including RFI, G:F, and partial efficiency of maintenance (PEM) were calculated. The lambs were sorted based on RFI and the 16 highest RFI (RFI ≥ mean + 0.5 SD) and 16 lowest RFI (RFI ≤ mean - 0.5 SD) lambs were subjected to body composition (BC) and DM digestibility (DMD) analysis. Feeding behavior traits (FB) were also evaluated for 24 h using a regular 5-min interval observation method. The high- and low-RFI lambs (14 lambs/RFI group) so classified in Exp. 1 were used in Exp. 2. Half of the lambs in each RFI group were randomly selected to be fed ad libitum or 85% of ad libitum (restricted feeding), which resulted in 4 experimental groups: 1) ad libitum high-RFI, 2) feed restricted high-RFI, 3) ad libitum low-RFI, and 4) feed restricted low-RFI. The lambs were fed the same diet as Exp. 1, and growth efficiency during a 6-wk test period as well as BC, DMD, and FB were also determined in Exp. 2. In Exp. 1, the low-RFI lambs consumed 14% ( < 0.01) less feed than high-RFI lambs. Differences were also observed between high- and low-RFI groups for G:F ( = 0.01), RFI ( < 0.01), and PEM ( < 0.01) in Exp. 1, but no differences were detected between high- and low-RFI lambs for ADG ( = 0.79), DMD ( = 0.42), BC ( > 0.72), and FB ( > 0.24). In Exp.2, the restriction feeding regime negatively affected ADG ( < 0.01) and G:F ( = 0.02) in low-RFI lambs, whereas G:F ( = 0.02) and PEM ( < 0.01) were improved in high-RFI lambs under the feed restriction condition. No effects of feed restriction on DMD ( = 0.87) and BC ( > 0.05) were observed. The lambs fed at the restricted level of intake presented a greater time ( < 0.01) and rate ( = 0.01) of eating than those fed ad libitum. Although bunk visits and feeding events were decreased ( < 0.01) with feed restriction, no interaction ( > 0.05) was detected between RFI phenotype and feeding regime for FB. In summary, feeding high-RFI lambs at 85% of ad libitum level improved G:F with no effect on ADG, whereas growth performance was reduced by feeding low-RFI lambs at 85% of ad libitum. However, these changes in feed efficiency were not related to DMD, BC, or FB.

Effect of dietary sugar concentration and sunflower seed supplementation on lactation performance, ruminal fermentation, milk fatty acid profile, and blood metabolites of dairy cows.

Previous research has shown that both sunflower seed (SF) and sucrose (SC) supplementation can result in variation in milk fat concentration and composition, possibly due to altered fermentation patterns and biohydrogenation of fatty acids in the rumen. The objective of this study was to determine the effects of different sugar concentrations with or without SF supplementation on lactation performance, ruminal fermentation, and milk fatty acid profile in lactating dairy cows. Eight multiparous Holstein dairy cows (body weight=620±15kg, 60±10 d in milk, mean ± standard deviation) were randomly assigned to treatments in a replicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Each 21-d period consisted of a 14-d diet adaptation period and 7-d collection period. Dairy cows were fed 1 of the following 4 diets: (1) no additional SC without SF supplementation (NSC-SF), (2) no additional SC with SF supplementation (NSC+SF), (3) SC without SF supplementation (SC-SF), and (4) SC with SF supplementation (SC+SF). The diets contained the same amount of forages (corn silage and alfalfa hay). Four isonitrogenous and isoenergetic diets were formulated by replacing corn grain with SC and SF and balanced using change in proportions of canola meal and sugar beet pulp. No interaction was detected between SC and SF supplementation with respect to dry matter intake, milk yield, and composition. A tendency was found for an interaction between inclusion of SC and SF on energy-corrected milk with the highest amount in the SC-SF diet. Ruminal pH and the molar proportion of acetate were affected by SC inclusion, with an increase related to the SC-SF diet. Diets containing SF decreased the concentrations of short-chain fatty acids (4:0 to 10:0) and medium-chain fatty acids (12:0 to 16:0) in milk fat. The addition of SC tended to decrease the concentration of total trans-18:1. These data provide evidence that exchanging SC for corn at 4% of dietary dry matter influenced milk fat content and rumen pH, resulting in a tendency for decreased concentration of trans-18:1 in milk fat. Sucrose alone did not alter the milk fatty acid profile when cows were fed a combination of unsaturated fat and sugar, although several significant interactions between sugar and unsaturated fat were observed.

Effect of forage inclusion and particle size in diets of neonatal lambs on performance and rumen development.

A slaughter experiment was conducted to determine the effects of alfalfa particle size on rumen morphology and performance of lambs. Twenty-four Balouchi lambs aged 21 days (9.1 ± 1.1 kg) were randomly fed control (diet without alfalfa hay; CON) and mixed rations containing 15% finely ground (FINE; 2 mm) and 15% coarsely chopped alfalfa hay (LONG; 3 to 4 cm). After a 63 days feeding period, nine animals (three per treatment) were slaughtered to obtain ruminal tissue samples for morphological analyses. Alfalfa particle size did not affect (p > 0.05) papillae density, height, width, epithelium depth and surface area. Coarse alfalfa decreased the stratum corneum and increased (p < 0.05) muscle depth compared with fine and control diets. Neither DNA content and nor RNA concentration of rumen tissue was affected by feeding different diets. Forage particle size did not affect the blood concentration of glucose, urea nitrogen (BUN), beta-hydroxybutyric acid (BHBA) and non-esterified fatty acids (NEFA). Dry matter intake and feed conversion ratio were higher for control diet; however, there were no significant differences between treatments for average daily gain. These data suggest that coarse alfalfa significantly reduces the stratum corneum and increases muscularity of rumen wall and tended to better feed conversion ratio.

Effect of Dietary Cation-Anion Difference during Prepartum and Postpartum Periods on Performance, Blood and Urine Minerals Status of Holstein Dairy Cow.

Twenty four periparturient cows were used to determine the effects of DCAD on acid-base balance, plasma and urine mineral concentrations, health status, and subsequent lactation performance. Each group of 12 cows received either a diet containing -100 DCAD or +100 DCAD for 21 d prepartum. Both anionic and cationic groups were divided into two groups, one received a +200 DCAD and the other +400 DCAD diet for 60 d postpartum. Prepartum reduction of DCAD decreased DMI, urinary and blood pH, urinary concentrations of Na or K and increased plasma and urinary Ca, Mg, Cl and S. Also cows fed -100 DCAD diet consumed the most dry matter in the first 60 d after calving. Postpartum +400 DCAD increased milk fat and total solid percentages, urinary and blood pH and urinary Na and K concentrations, but urinary Ca, P, Cl and S contents decreased. Greater DMI, FCM yields were observed in cows fed a diet of +400 DCAD than +200 DCAD. No case of milk fever occurred for any diets but feeding with a negative DCAD diet reduced placenta expulsion time. In conclusion, feeding negative DCAD in late gestation period and high DCAD in early lactation improves performance and productivity of dairy cows.

The effects of feeding clinoptilolite on hematology, performance, and health of newborn lambs.

The effects of feeding clinoptilolite on hematology, performance, and health of newborn Balouchi lambs were evaluated in this experiment. In a completely randomized design, 30 newborn lambs were allocated to three groups and fed by basal diet (C0; without clinoptilolite) and C1 and C2 (the basal diet plus 1.5% and 3% clinoptilolite, respectively, for 6 weeks (3 weeks before and 3 weeks after weaning)). Blood samples were taken from all lambs, at the time when the animals were allocated to the experimental diet and at the end of each week of experiment, and analyzed for hematology, plasma fibrinogen, and total protein. Performance and health of all lambs were measured. Fecal consistency score and diarrhea severity were evaluated. There was no difference between lambs in case of hematological parameters. Lambs fecal consistency score and severity of diarrhea were lowest (P < 0.05) for lambs on C1 and C2 and highest for lambs on C0. Dry matter intake and feed conservation ratio were similar between the groups of lambs fed by different diets, but daily gain of lambs differed significantly (P < 0.05) and was higher in C2. It was concluded that addition of 3% clinoptilolite to starter diet of newborn lamb can reduce incidence and severity of diarrhea, although its effect on hematology and performance was negligible.

The effects of feed bunk competition on the feed sorting behavior of close-up dry cows.

The objectives of this research were to describe the feed sorting, feeding behavior, and feed intake of cows consuming a close-up ration and to determine if these behaviors are affected by competition for access to the feed bunk. Thirty-six dry Holstein cows, consuming a close-up total mixed ration diet, were assigned to 1 of 2 treatments: 1) noncompetitive (1 cow/feed bin) or 2) competitive (2 cows/feed bin). Dry matter intake, feeding behavior, and sorting behavior were monitored for each feed bin on 4 separate days during wk 2 and 3 before the anticipated calving dates of the cows. Fresh feed and orts were sampled daily from each bin and were subjected to particle size analysis. The particle size separator consisted of 3 screens (18, 9, and 1.18 mm) and a bottom pan resulting in 4 fractions (long, medium, short, and fine). Sorting was calculated as the actual intake of each particle size fraction expressed as a percentage of the predicted intake of that fraction. Regardless of treatment, the cows sorted against long particles and for short and fine particles. Competition at the feed bunk had no effect on the sorting behavior, dry matter intake, or feeding time of the cows, but did dramatically increase the feeding rate of the cows. The competitively fed cows also had fewer meals per day, and tended to have larger and longer meals. Our results suggest that increased competition at the feed bunk promotes feeding behavior patterns that will likely increase the between-cow variation in composition of total mixed ration consumed.

Digestion of feed amino acids in the rumen and intestine of steers measured using a mobile nylon bag technique.

The disappearance of dry matter (DM), crude protein (CP), and amino acids (AA) in steers after rumen incubation and intestinal passage of alfalfa hay, barley hay, corn silage, barley grain, corn grain, wheat bran, meat meal, fish meal, cottonseed meal, and soybean meal were measured in 3 steers using a mobile nylon bag technique. Ruminal degradation of individual AA differed between feedstuffs. For barley hay and corn silage, the ruminal disappearance of total AA was higher and lower than the other feedstuffs, respectively. The intestinal digestibility of total AA in alfalfa hay was lower than the digestion of CP. The intestinal digestibility of Arg and His was higher than that of total AA in alfalfa hay, meat meal, cottonseed meal, soybean meal, barley hay, and wheat bran. In addition, the intestinal digestibility of Lys was higher than that of total AA in alfalfa hay, meat meal, cottonseed meal, soybean meal, barley hay, corn silage, and wheat bran. The intestinal disappearance of CP in most cases was higher than that of DM. The results indicated that feedstuffs with lower ruminal disappearance of DM, CP, total AA, essential AA, and nonessential AA generally had a higher intestinal disappearance, resulting in a relatively constant total tract disappearance. These results could be used to improve the current system of diet formulation in ruminants.

Effects of alfalfa particle size and specific gravity on chewing activity, digestibility, and performance of Holstein dairy cows.

Two experiments were carried out to test the effects of alfalfa particle size and functional specific gravity (FSG) on chewing activity, digestibility, rumen kinetics, and production of lactating dairy cows fed corn silage based rations. In experiment 1, water-holding capacity (WHC), insoluble dry matter, hydration rate, and FSG changes were determined in alfalfa hay (varying in particle size) and corn silage. Reduction of particle size increased bulk density, FSG, and the rate of hydration, and decreased WHC of alfalfa. In experiment 2, 9 midlactation Holstein dairy cows fed total mixed rations containing 3 sizes of alfalfa hay (with geometric mean 7.83, 4.04, and 1.14 mm) were used in a replicated 3 x 3 Latin square design. The diets contained 20, 20, 35, 7, 7.5, 10, 0.3, 0.1, and 0.1% of DM alfalfa, corn silage, barley, soybean meal, beet pulp, wheat bran, dicalcium phosphate, vitamin premix, and salt, respectively. The geometric means (GM) of rations were 3.34, 2.47, and 1.66 mm in long, medium, and fine alfalfa treatments, respectively. Reduction of particle size increased daily NDF intake (kg), but decreased the proportion of physically effective factor (pef) and physically effective NDF (peNDF) in the ingested rations. Reduction of particle size increased the FSG of rations and intake of DM but reduced digestibility of NDF and ash. Reduction of particle size decreased ruminal mean retention time (RMRT), but increased the ruminal particulate passage rate. Milk and FCM yield were not affected by treatments. The rumen pH, total chewing activity, rumination, eating time, and milk fat were reduced as particle size decreased, but milk protein increased. This study showed that reduction of forage particle size increased bulk density, FSG, and hydration rate of alfalfa and was the most influential factor affecting DMI, milk composition, and chewing behavior. Reduction of forage particle size had minimal impact on digestibility and milk production.

Effects of bombardment on optical properties during the deposition of silicon nitride by reactive ion-beam sputtering.

Thin silicon nitride (Si(1_x)N(x)) films were synthesized without substrate heating by means of reactive argon-ion sputtering of either silicon or a silicon nitride target in the 1000-1500-eV energy range at a nitrogen partial pressure of 1.3 × 10(-2) Pa and with simultaneous nitrogen ion-assisted bombardment in the 300-500-eV low energy range. The extinction coefficient and refractive index of the films were directly dependent on the N(+) ion-to-atom arrival ratio, assisted ion energy, film growth rate, and indicated a correlation with film stoichiometry and disorder. Si(3)N(4) films were obtained for N(+) ion/Si atom arrival ratios from 0.6 to 1.7 and for different Si:N atom arrival rates and had a refractive index as high as 2.04 (633 nm) and a low hydrogen content as indicated by IR spectra.